A combine harvester or combine is a machine that harvests crops. A coverage map of a combine displays regions of the field that have been harvested by that combine. A coverage map allows the operator of the combine know that a region of the field has already been harvested by the same combine. The yield calculation for the yield map is altered if only a partial header width as opposed to a full header width is being harvested by the combine. Otherwise, the combine and yield calculation will not know if the combine is only harvesting a partial header width due to a region of the field that has already been harvested by this combine.